Methods and apparati for quickset gas lift separation and liquid storage

ABSTRACT

The present disclosure provides methods and apparati for separating liquids from production gases and recovering the liquids. The methods and apparati of the present disclosure can reduce or eliminate emissions compared to standard methods and devices and also eliminate the need for haul away of liquids by collecting compressor system liquids in charge vessel(s). The methods and apparati of the present disclosure can also be used to fuel the engines which operate the compressor systems using gas from the compressor drains and the gas used to drain the charge vessel(s).

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a Continuation application of InternationalApplication No. PCT/US19/36625, filed Jun. 11, 2019, which claimspriority to U.S. Provisional Application No. 62/683,209, filed Jun. 11,2018, the disclosure of each of which is incorporated herein byreference in its entirety.

BACKGROUND

In the oil and gas industry, gas lift technology uses an external sourceof high-pressure gas for supplementing formation gas to lift wellfluids. Typically, in the production of oil from oil wells by gas liftsystems, gas separated from the oil is compressed by a compressor toincrease its pressure and recycled for further production of oil. Afterthe compression stage, the gas is returned to the production wells asgas lift gas. In typical gas lift systems, fluids produced from theseparation process are routed into haul off tanks on the surface. Thefluids from the haul off tanks are collected by haul off trucks. Everytime the fluids from the separation process are released to the haul offtanks during a dump cycle, gas emissions are released into theatmosphere. Further liquids that are stored in the haul off tankscontinually turn to vapor, releasing gas emissions to the atmosphere.

It is desirable to have methods and apparati configured for gas liftseparation and fluid storage which reduce or eliminate atmosphericemissions and the need for haul off trucks.

SUMMARY

The present disclosure provides methods and apparati for quickset gaslift separation and liquid storage.

In some embodiments, an apparatus is provided that comprises an inletseparator configured to receive production gas and to separate entrainedliquids from the production gas to form a gas lift gas, the inletseparator the can include a production gas inlet, a gas lift gas outletconfigured to be fluidically connected to a compressor system comprisingat least one engine capable of being operated using the gas lift gas asfuel, and a liquid outlet as well as a first charge vessel that caninclude a first liquid inlet fluidically connected to the liquid outletof the inlet separator, a first charge gas valve configured to befluidically connected to a high pressure gas source in the compressorsystem and further configured to deliver high pressure gas to drain thefirst charge vessel when the first charge gas valve is in an openconfiguration, a liquid outlet fluidically connected to a first dumpvalve, the first dump valve allowing liquid from the first charge vesselto flow out of the first charge vessel when the first dump valve is inan open position and preventing the flow of liquid from the first chargevessel when the first dump valve is in a closed position, and a gasoutlet configured to be fluidically connected to the at least oneengine.

In some embodiments, a method for recovering lift gas lift gas andliquids from production gas can include feeding a production gas to aninlet separator fluidically connected to a first charge vesselconfigured to receive liquids, the inlet separator being configured toremove liquids from the production gas and deliver the liquids to thefirst charge vessel and to generate a gas lift gas, the inlet separatorbeing further fluidically connected to a compressor system comprising atleast one engine and configured to deliver gas lift gas to thecompressor system, and the step of allowing gas lift gas from the firstcharge vessel to flow into the at least one engine in the compressorsystem, the first charge vessel comprising a gas outlet fluidicallyconnected to the at least one engine, the gas lift gas being suitable tooperate the at least one engine.

In some embodiments, an apparatus can include an inlet separatorconfigured to receive production gas and to separate entrained liquidsfrom the production gas to form a gas lift gas, the inlet separate caninclude a production gas inlet, a gas lift gas outlet configured to befluidically connected to a compressor system and a liquid outlet, and afirst charge vessel that can include at least one liquid inletfluidically connected to the liquid outlet of the inlet separator, atleast one of the at least one liquid inlet being configured to befluidically connected to the compressor system to receive liquids fromthe compressor system, a first charge gas valve configured to befluidically connected to a high pressure gas source in the compressorsystem and further configured to deliver high pressure gas to drain thefirst charge vessel when the first charge gas valve is in an openconfiguration, a liquid outlet fluidically connected to a first dumpvalve, the first dump valve allowing liquid from the first charge vesselto flow out of the first charge vessel when the first dump valve is inan open position and preventing the flow of liquid from the first chargevessel when the first dump valve is in a closed position, and a gasoutlet configured to be fluidically connected to the compressor system.

In some embodiments, a method for recovering gas lift gas and liquidsfrom production gas can include feeding a production gas to an inletseparator fluidically connected to a first charge vessel configured toreceive the liquids, the inlet separator being configured to removeliquids from the production gas and deliver the liquids to the firstcharge vessel and to generate a gas lift gas, the inlet separator beingfurther fluidically connected to a compressor system and configured todeliver gas lift gas to the compressor system, and allowing liquidsgenerated by the compressor system to flow into the first charge vessel,the first charge vessel being configured to be fluidically connected tothe compressor system.

In some embodiments, an apparatus of the present disclosure includes afuel filter comprising a gas inlet, a liquid outlet, and a gas outletconfigured to be fluidically connected to at least one engine capable ofbeing operated using a gas lift gas as fuel in a compressor system, thefluidic connection between the gas outlet and the at least one engineincluding a pressure control valve configured to allow a suitablepressure of gas lift gas to the at least one engine to operate the atleast one engine, an inlet separator configured to receive productiongas and to separate entrained liquids from the production gas to formthe lift gas, the inlet separator including a production gas inlet, agas lift gas outlet configured to be fluidically connected to thecompressor system, a liquid outlet, a gas make up outlet fluidicallyconnected to the fuel filter, the fluid connection between the gas makeup outlet and the fuel filter including a fuel gas make up valve, thefuel gas make up valve being configured to allow sufficient gas lift gasto flow from the inlet separator to the fuel filter to maintain apressure suitable to operate the at least one engine, and a gas chargeoutlet fluidically connected to the fuel filter, the fluidic connectionbetween the gas charge outlet and the fuel filter comprising a fuelfilter charge valve configured to deliver gas lift gas to the fuelfilter to drain liquids form the fuel filter when the fuel filter chargevalve is in an open configuration, and a first charge vessel that caninclude at least one liquid inlet fluidically connected to the liquidoutlet of the inlet separator and the liquid outlet of the fuel filter,at least one of the at least one liquid inlet being configured to befluidically connected to the compressor system to receive liquids fromthe compressor system, a gas de pressure outlet fluidically connected tothe inlet separator, the fluidic connection between the gas de pressureoutlet and the inlet separator comprising a de pressure valve, a firstcharge gas valve configured to be fluidically connected to a highpressure gas source in the compressor system and further configured todeliver high pressure gas to drain the first charge vessel when thefirst charge gas valve is in an open configuration and the de pressurevalve is in a closed configuration, a liquid outlet fluidicallyconnected to a first dump valve, the first dump valve allowing liquidfrom the first charge vessel to flow out of the first charge vessel whenthe first dump valve is in an open configuration and preventing the flowof liquid from the first charge vessel when the first dump valve is in aclosed configuration, and a gas outlet fluidically connected to the fuelfilter and configured to deliver gas lift gas to the fuel filter tooperate the at least one engine.

In some embodiments, a method for recovering gas lift gas and liquidsfrom production gas can include feeding a production gas to an apparatusof the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The summary above, as well as the following detailed description ofillustrative embodiments, is better understood when read in conjunctionwith the appended drawings. For the purpose of illustrating the presentdisclosure, exemplary constructions of the disclosure are shown in thedrawings. However, the disclosure is not limited to specific methods andinstrumentalities disclosed herein.

FIG. 1 is an exemplary schematic view of the overall facility of anembodiment of the present disclosure.

FIG. 2 depicts another schematic view of the overall facility of theembodiment shown in FIG. 1.

FIG. 3 depicts a perspective view of an exemplary gas lift quicket skid.

FIG. 4 depicts an exemplary apparatus of the present disclosure.

FIG. 5 depicts an exemplary apparatus of the present disclosure.

FIG. 6A depicts a front perspective view of an exemplary apparatus ofthe present disclosure.

FIG. 6B depicts a rear perspective view of the exemplary apparatus ofFIG. 6A.

FIG. 7 depicts another exemplary apparatus of the present disclosure.

DESCRIPTION

While methods, systems and devices are described herein by way ofexamples and embodiments, those skilled in the art recognize themethods, systems and devices are not limited to the embodiments ordrawings described. It should be understood that the drawings anddescription are not intended to be limited to the particular formdisclosed. Rather, the intention is to cover all modifications,equivalents and alternatives falling within the spirit and scope of theappended claims and description. Any headings used herein are fororganization purposes only and are not meant to limit the scope of thedescription of the claims. As used herein, the word “may” is used in apermissive sense (i.e., meaning having the potential to) rather than themandatory sense (i.e., meaning must). Similarly, the words “include,”“including,” and “includes” mean including, but not limited to. Thepresent disclosure describes particular embodiments and with referenceto certain drawings, but the subject matter is not limited thereto.

The present disclosure will provide description to the accompanyingdrawings, in which some, but not all embodiments of the subject matterof the disclosure are shown. Indeed, the subject matter may be embodiedin many different forms and should not be construed as limited to theembodiments set forth herein, rather, these embodiments are provided sothat this disclosure satisfies all the legal requirements.

The basic components of certain embodiments are described herein. Asused in the description, the terms “top,” “bottom,” “above,” “below,”“over,” “under,” “beneath,” “on top,” “underneath,” “up,” “down,”“upper,” “lower,” “front,” “rear,” “back,” “forward” and “backward”refer to the objects referenced when in the orientation illustrated inthe drawings, which orientation is not necessary for using the devicesor achieving the methods described herein.

Definitions

Certain terminology is used in the following description for convenienceonly and is not limiting. Certain words used herein designate directionsin the drawings to which reference is made. Unless specifically setforth herein, the terms “a,” “an” and “the” are not limited to oneelement, but instead should be read consistent with the meaning of “oneor more,” “at least one,” and “one or more than one.” As used herein“another” means at least a second or more. The terminology includes thewords noted above, derivatives thereof and words of similar import.

The use of the term “or” in the claims is used to mean “and/or” unlessexplicitly indicated to refer to alternatives only or the alternativesare mutually exclusive.

Use of the term “about”, when used with a numerical value, is intendedto include +/−10%. For example, if a number of amino acids is identifiedas about 200, this would include 180 to 220 (plus or minus 10%).

“Fluidically connected” as used herein refers to a physically connectedstate, such as, by way of example but not limitation, by interconnectedpiping, which permits the flow of a fluid, which can include either aliquid or gas or both.

Unless otherwise defined, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art.

The present disclosure generally relates to methods and apparati forprocessing production gas to separate out and recycle gas lift gas foruse in obtaining oil from wells and for separating an obtaining fluidsfrom the production gas and gas lift gas while it is processed in thecompressor package.

As shown in FIG. 1, a general workflow of the processing of productiongas according to the present disclosure is shown. FIG. 2 depicts theworkflow in FIG. 1 using five gas compression systems connected to asingle gas lift quickset skid 1. The gas lift quickset skid can includethe inlet separator 2 and the charge vessel 3. As shown in FIGS. 1 and2, production gas can be received along an inlet pipeline into the gaslift quickset skid, which can be mobile. The gas lift quickset skidincludes the inlet for introducing the production gas into an inletseparator which can separate entrained liquids from the production gas,the entrained liquids being stored in a charge vessel. The gas liftquickset skid is fluidically connected to a gas compression system wherethe gas lift gas separated from the production gas is compressed forrecycling for use in obtaining oil from the well. Gas lift gas from theinlet separator can be metered on the quickset skid before beingdischarged into the gas compression system 4 where it is compressed tohigh pressures. Additional metering skids and compression skids can beused to provide for parallel compressor operations. The fluidicconnections between the gas lift quicket skid and the gas compressionsystem can allow for the flow of gas and liquids between the two, asliquids can be produced by the gas compression system which areundesirable in the final gas lift gas for use in the well. Becauseliquids are produced in the process of gas compression, these liquidscan be separated by scrubbers in the compression system and can bedumped to the charge vessel. By diverting the liquids from thecompressor system to the charge vessel, these liquids can be combinedwith those from the inlet separator and dumped from the charge vesselfor subsequent use or storage. When the liquid in the charge vesselreaches a certain level, charge gas from the gas compression systems canbe used to drive the liquid out of the charge vessel and to a flow lineor tank battery. For example, charge gas from a second interstagescrubber of the gas compression system can be used to drive liquids outof the charge vessel. The pressurized gas will displace the accumulatedliquids from the charge vessel for some short time interval and thecharge vessel will depressurize and again return to normal operation. Asan alternative, a pneumatic or electrically driven pump may be providedto pump liquids from the charge vessel if liquid supply pressure in theliquid line is required. The separated liquids can then flow via apipeline to an offsite tank battery. The gas lift quicket skid can alsoallow loading and unloading via winch truck and rolling tailboard.

As shown in FIG. 3, an exemplary gas lift quickset skid 1 can include aninlet separator 2 and a charge vessel 3. The charge vessel can also beinsulated with charge vessel insulation 5.

Production fluids from oil or gas wells will typically be processed at acentral production facility from which some of the separated process gaswill be transferred via pipeline to the gas lift skid. The gas lift skidmay be located at a considerable distance from the production facilitywhere process gas is being transferred from via pipeline in someinstallations. The supply gas arrival temperature at the quickset skidwill vary and gas typically will arrive at ambient conditions. The gassupply pressure can vary from, by way of example but not limitation, 15psig to 250 psig. The inlet separator located on the quickset skidremoves entrained liquids from the gas before the gas is transferred toan adjacent compressor skid, generally provided by others. A multistagegas engine driven reciprocating compressor located on the adjacent skidcan compress the gas, by way of example, but not limitation, about 1000to 1500 psig, where the discharge gas will be returned to the oil or gaswells for use as gas lift gas. A slip stream taken from the compressorinlet scrubber or charge gas separator can be used as fuel gas in thecompressor gas engine. Utility gas from the compressor interstagescrubber(s) can also return to the quickset skid and can be used todisplace the accumulated liquids from the charging vessel to a remotetank farm storage facility.

The inlet separator can be a horizontal vessel that facilitates removalof liquids from the production gases. Inlet separators are known tothose of skill in the art. The liquids from the inlet separator can bedischarged under level control and sent to a charge vessel. The chargevessel can store liquids from both the inlet separator and the adjacentcompressor interstage scrubbers. Liquids from the charge vessel canperiodically discharge to the storage facility which typically may belocated a mile from the quickset skid. The pressure in the charge vesselcan be increased, by way of example but not limitation up to 180 psig,while liquids are being discharged to the tank farm. Isolation valvesand check valves can be used to prevent gas discharge to the other flowlines while the charge vessel is pressurized with high pressure gas asshown in FIGS. 4 and 7. Gas from the charge vessel can normally recycleto the inlet separator or provide fuel gas to the compressor gasengines.

To prevent and control algae and other organic growth in the liquidlines downstream of the charge vessel, the injection of suitablechemicals can be provided. The buildup of any growth in the dischargepipeline can be determined by monitoring the pressure drop in thedischarge piping which could significantly increase over time duringnormal operation.

The quickset skid can collect critical information and measurements andprovide early warning to operators of potential or developing problems.The control and safety system devices can employ a combination ofpneumatic, electrical and wireless technology to provide the desiredfunctionality.

In some embodiments, an apparatus is provided which comprises an inletseparator and a first charge vessel. The inlet separator is configuredto receive production gas through a production gas inlet and to separateentrained liquids from the production gas to form a gas lift gas. Theinlet separator is fluidically connected to the first charge vessel viaa liquid outlet on the inlet separator and a liquid inlet on the firstcharge vessel. The inlet separator is also configured to be fluidicallyconnected to a compressor system via a gas lift gas outlet. The firstcharge vessel also includes a liquid outlet and a first charge gas valvethat is configured to be fluidically connected to a high pressure gassource in the compressor system and further configured to deliver highpressure gas to drain the first charge vessel by applying the highpressure gas to the liquid in the first charge vessel.

In some embodiments, the fluidic connection between the inlet separatorand the first charge vessel comprises an inlet separator dump valve, theinlet separator dump valve being configured to allow liquid to flow fromthe inlet separator to the first charge vessel when the inlet separatordump valve is in a first (“open”) configuration and prevent the flow ofliquid to the first charge vessel when the inlet separator dump valve isin a second (“closed”) configuration. In some embodiments, the inletseparator dump valve can be operatively connected to an inlet separatorlevel controller that is also operatively connected to the inletseparator. In some embodiments, the inlet separator level controller andinlet separator dump valve can be fluidically connected to the inletseparator such that they receive supply gas from the inlet separatorsufficient to operate the inlet separator level controller and inletseparator dump valve. In some embodiments, the inlet separator levelcontroller is configured to open the inlet separator dump valve when aliquid level in the inlet separator exceeds an inlet separator targetliquid level, and is also configured to close the inlet separator dumpvalve when the liquid level in the inlet separator is less than theinlet separator target liquid level or below a minimum inlet separatorliquid level. The inlet separator target liquid level and the minimuminlet separator liquid level can be determined by one of skill in theart depending on the design of the inlet separator and the first chargevessel.

In some embodiments, the liquid outlet of the first charge vessel isfluidically connected to a first dump valve that is configured to allowliquids from the first charge vessel to flow out of the first chargevessel when the first dump valve is in a first (“open”) configurationand to prevent the flow of liquid from the first charge vessel when thefirst dump valve is in a second (“closed”) position. In someembodiments, the first dump valve and the first charge valve areoperatively connected to a first charge vessel level controller that isoperatively connected to the first charge vessel. The first chargevessel level controller, first charge gas valve and first dump valve canbe fluidically connected to the inlet separator such that they receivesupply gas from the inlet separator sufficient to operate the firstcharge vessel level controller, first charge gas valve and first dumpvalve. In some embodiments, the first charge vessel can further comprisea gas de pressure outlet fluidically connected to the inlet separator.In some embodiments, the fluidic connection between the gas de pressureoutlet and the inlet separator can include a de pressure valve. In suchembodiments, the first charge vessel level controller can be furtheroperatively connected to the de pressure valve and the de pressure valvecan be fluidically connected to the inlet separator such that itreceives supply gas from the inlet separator sufficient to operate thede pressure valve. In some embodiments, the first charge vessel levelcontroller can be configured to open the first dump valve and firstcharge valve and, if present, close the de pressure valve when a liquidlevel in the inlet separator exceeds an inlet separator target liquidlevel, and can also be configured to close the first charge valve andfirst dump valve and to open the de pressure valve, if present, when theliquid level in the first charge vessel is less than the first chargevessel target liquid level or below a minimum first charge vessel liquidlevel. The first charge vessel target liquid level and the minimum firstcharge vessel liquid level can be determined by one of skill in the artdepending on the design of the first charge vessel.

In some embodiments, the first charge vessel can include a gas outletconfigured to be fluidically connected to at least one engine in thecompressor system, the at least one engine being capable of beingoperated using the gas lift gas. In some embodiments, the apparatus canfurther comprise a fuel filter that can include a gas inlet fluidicallyconnected to the gas outlet of the first charge vessel, a liquid outlet,and a gas outlet that is configured to be fluidically connected to theat least one engine. In some embodiments, the fluidic connection betweenthe gas outlet of the fuel filter and the at least one engine caninclude a pressure control valve configured to allow a suitable pressureof gas lift gas to the at least one engine to operate the at least oneengine. In some embodiments, the fluidic connection between the pressurecontrol valve and the at least one engine can include a pressure sensorconfigured to detect a pressure to the at least one engine, where theinlet separator further comprises a gas make up outlet fluidicallyconnected to the fuel filter, the fluid connection between the gas makeup outlet and the fuel filter comprising a fuel gas make up valveoperatively connected to the pressure sensor, the pressure sensor beingconfigured to open or close the gas make up valve sufficiently todeliver a suitable pressure of gas lift gas to the at least one engineto operate the at least one engine, where the fuel gas make up valve isconfigured to allow sufficient gas lift gas to flow from the inletseparator to the fuel filter to maintain a pressure suitable to operatethe at least one engine. Thus, for example, where the gas pressure fromthe first charge vessel that flows through the fuel filter is too low tomaintain operation of the at least one engine, the fuel gas flow to theat least one engine can be supplemented with gas from the inletseparator. This configuration, where gas is transferred from the firstcharge vessel to the at least one engine can also assist in depressurizing the first charge vessel which can aid in the flow ofliquids into the first charge vessel, especially where those liquids areat a pressure below that which is typically in the first charge vesselwithout the de pressurization.

In some embodiments, where a fuel filter is included, the inletseparator can further include a gas charge outlet fluidically connectedto the fuel filter, the fluidic connection between the gas charge outletand the fuel filter including a fuel filter charge valve that can beconfigured to deliver a gas lift gas to the fuel filter to drain liquidsfrom the fuel filter when the fuel filter charge valve is in an “open”configuration. In some embodiments, the liquid drain from the fuelfilter can flow from the liquid outlet of the fuel filter into the firstcharge vessel to capture the liquids. In some embodiments, the fuelfilter can be operatively connected to a fuel filter level controllerthat is operatively connected to the fuel filter charge valve. The fuelfilter level controller and fuel filter charge valve can be fluidicallyconnected to the inlet separator to receive supply gas for theiroperation. In some embodiments, the fuel filter level controller can beconfigured to open the fuel filter charge valve when a liquid level inthe fuel filter exceeds a fuel filter target liquid level and can beconfigured to close the fuel filter charge valve when the liquid levelin the fuel filter is less than the fuel filter target liquid level or aminimum fuel filter liquid level. The fuel filter target liquid leveland minimum fuel filter liquid level can be determined by one of skillin the art based on the design of the fuel filter.

In some embodiments, the first liquid inlet or an additional inlet ofthe first charge vessel can be configured to be fluidically connected tothe compressor system to receive liquids from the compressor system. Insome embodiments, the liquids from the compressor system can be from asource chosen from a fuel filter, an inlet or suction scrubber, aninterstage scrubber or environmental drains of the compressor system. Insome instances, where the pressure in the first charge vessel is higherthan the environmental drains or other liquid flows from the compressorsystem, the apparatus can further include a drain drum and a drain pump,the drain drum being fluidically connected to the drains from thecompressor system and the drain pump being fluidically connected to agas source from the compressor that is at a higher pressure than thefirst charge vessel such as, by way of example but not limitation, aninterstage scrubber such as the second interstage scrubber.

In any of the foregoing embodiments, the apparatus can further comprisea flow meter or device fluidically connected to the gas lift gas outlet,the flow meter or device configured to measure the flow rate of gas orto limit the flow of gas to the compressor system. In any of theforegoing embodiments, the apparatus can also further comprise a secondcharge vessel that includes at least one liquid inlet configured to befluidically connected to the compressor system to receive liquids fromthe compressor system, a second charge gas valve configured to befluidically connected to the high pressure gas source in the compressorsystem to deliver high pressure gas to drain the second charge vesselwhen the second charge gas valve is in an open configuration, and aliquid outlet fluidically connected to a second dump valve, the seconddump valve allowing liquid from the second charge vessel to flow outwhen the second dump valve is in a first (“open”) configuration and toprevent the flow of liquid when the second ump valve is in a second(“closed”) configuration. In some embodiments, the second charge vesselis configured to receive liquids from the second interstage scrubber ofthe compressor system. In some embodiments, the second charge vessel canbe operatively connected to a second charge vessel level controller thatis operatively connected to the second charge gas valve and the seconddump valve. The second charge vessel level controller, second charge gasvalve and the second dump valve can be fluidically connected to theinlet separator to receive supply gas for their operation. In someembodiments, the second charge vessel level controller is configured toopen the second charge gas valve and open the second dump valve when aliquid level in the second charge vessel exceeds a second charge vesseltarget liquid level and to close the second charge gas valve and thesecond dump valve when the liquid level in the second charge vessel isless than the second charge vessel target liquid level or a minimumsecond charge vessel liquid level. The second charge vessel targetliquid level and minimum second charge vessel liquid level can bedetermined by one of skill in the art based on the design of the secondcharge vessel. In some embodiments, the second charge vessel can befluidically connected to a charge vessel pressure regulator fluidicallyconnected to the second charge vessel and the inlet separator, that isconfigured to relieve excess pressure in the second charge vessel.

In any of the foregoing embodiments, the first charge vessel or thesecond charge vessel can further include a safety valve configured torelive excess pressure in the first charge vessel or second chargevessel, respectively. In any of the foregoing embodiments, the firstcharge gas valve or second charge gas valve can be fluidically connectedto a charge gas pressure regulator configured to deliver a target chargegas pressure, the charge gas pressure regulator being connected to thehigh pressure gas source. In some embodiments, the high pressure gassource for the first charge vessel and second charge vessel can be thesame source. In some embodiments, the high pressure gas source has ahigher pressure than the vessel which it is being used to drain. Forexample, when gas from the first charge vessel is used to fuel at leastone engine and is depressurized to the inlet separator, the highpressure gas source need not be as high to discharge the first chargevessel, particularly if a second charge vessel is employed to receivehigh pressure outputs. As such, in embodiments of the presentdisclosure, the Joule-Thompson effect caused by the difference betweenthe pressure being used to “push” and the pressure in the vessel being“pushed” can be reduced. This high pressure gas source in any of theforegoing embodiments can be a source in the compressor system chosenfrom a first interstage scrubber, a second interstage scrubber, a thirdinterstage scrubber or final discharge of the compressor system.

In some embodiments of the present disclosure the environmentalemissions and discharge of gas can be minimized or eliminated, thusresulting in no requirement for a mechanism for burnoff. By way ofexample, but not limitation, where the compressor system is drained intoa charge vessel, including a first charge vessel and second chargevessel, and the gas from the first charge vessel is used to fuel atleast one engine in the compressor system, no gas emissions arenecessary as the gas is consumed as fuel for the at least one engine asopposed to standard practices which include venting compressor liquiddrains to atmosphere. Further, in embodiments of the present disclosure,no haul away of liquids may be required as the liquids are flowed intocharge vessels which can then be used to flow the liquids to off sitetank battery storage.

In any of the foregoing embodiments, the inlet separator, first chargevessel, second charge vessel and fuel filter, to the extent they arepresent, can all be located on a single skid. In any of the foregoingembodiments, an apparatus can be fluidically connected to two or morecompressor systems. In any of the foregoing embodiments, supply gas thatis used to operate valves or other devices, such as level controllers,can be fed from any suitable source of supply gas or other gas that issuitable to operate the devices. In any of the foregoing embodiments,additional valves, regulators, sensors, and meters can be added tofurther control or monitor the system.

Methods of the present disclosure can include methods of recovering gaslift gas and liquids from production gas that comprise feeding aproduction gas to an apparatus of the present disclosure. In someembodiments, a method of the present disclosure includes the steps offeeding a production gas to an inlet separator fluidically connected toa first charge vessel configured to receive liquids, the inlet separatorbeing configured to remove liquids from the production gas and deliverthe liquids to the first charge vessel and to generate a lift gas, theinlet separator being further fluidically connected to a compressorsystem comprising at least one engine and configured to deliver gas liftgas to the compressor system, and allowing gas lift gas from the firstcharge vessel to flow into the at least one engine in the compressorsystem, the first charge vessel comprising a gas outlet fluidicallyconnected to the at least one engine, the gas lift gas being suitable tooperate the at least one engine. In some embodiments, the method caninclude allowing liquids generated by the compressor system to flow intothe first charge vessel via a fluidic connection between a source of theliquids generated by the compressor system. In some embodiments, theliquids are a portion of the liquids generated by the compressor system.In some embodiments, the portion of liquids can include sources chosenfrom at least one of a fuel filter, an inlet or suction scrubber, aninterstage scrubber and an environmental drain of the compressor system.In some embodiments, a second charge vessel is provided and liquidsgenerated by the compressor system are allowed to flow into the secondcharge vessel via a fluidic connection between the source of the liquidsand the second charge vessel. The liquids flowed into the second chargevessel can include a portion of liquids generated by the compressorsystem such as, by way of example but not limitation, the liquids from asecond interstage scrubber of the compressor system. In someembodiments, the methods further include the step of pushing liquid outof the first charge vessel or second charge vessel, if present, using ahigh pressure gas source from the compressor system such as, by way ofexample but not limitation, from a first interstage scrubber, a secondinterstage scrubber, a third interstage scrubber and a final dischargefrom the compressor system, where the high pressure gas source isfluidically connected to the first charge vessel and second chargevessel, if present. The high pressure gas source is higher than thepressure in the vessel which is to be “pushed.”

In some embodiments, a method of the present disclosure includes thesteps of feeding a production gas to an inlet separator fluidicallyconnected to a first charge vessel configured to receive liquids, theinlet separator being configured to remove liquids from the productiongas and deliver the liquids to the first charge vessel and to generate alift gas, the inlet separator being further fluidically connected to acompressor system, and allowing liquids generated by the compressorsystem to flow into the first charge vessel which is fluidicallyconnected to the compressor system. In some embodiments, the method caninclude allowing gas to flow from the first charge vessel to at leastone engine in the compressor system. In some embodiments, the liquidsare a portion of the liquids generated by the compressor system. In someembodiments, the portion of liquids can include sources chosen from atleast one of a fuel filter, an inlet or suction scrubber, an interstagescrubber and an environmental drain of the compressor system. In someembodiments, a second charge vessel is provided and liquids generated bythe compressor system are allowed to flow into the second charge vesselvia a fluidic connection between the source of the liquids and thesecond charge vessel. The liquids flowed into the second charge vesselcan include a portion of liquids generated by the compressor system suchas, by way of example but not limitation, the liquids from a secondinterstage scrubber of the compressor system. In some embodiments, themethods further include the step of pushing liquid out of the firstcharge vessel or second charge vessel, if present, using a high pressuregas source from the compressor system such as, by way of example but notlimitation, from a first interstage scrubber, a second interstagescrubber, a third interstage scrubber and a final discharge from thecompressor system, where the high pressure gas source is fluidicallyconnected to the first charge vessel and second charge vessel, ifpresent. The high pressure gas source is higher than the pressure in thevessel which is to be “pushed.” In some embodiments, the method furtherincludes a step of pumping a portion of liquids from the compressorsystem to the first charge vessel. In some embodiments, this pumpedportion of liquids from the compressor system is an environmental drainof the compressor system or any other liquid source that is under lesspressure than the pressure in the first charge vessel. In someembodiments, the pump used can be connected to a higher pressure gassource from the compressor system and can pump the liquids from a draindrum in which they have collected from the compressor system.

In any of the foregoing embodiments, the methods can result in reducedor eliminated gas emissions. In any of the foregoing embodiments, themethods may not include the step of burning gas emissions.

Non-limiting, exemplary gases and their compositions that can be used inthe apparati of the present disclosure and which are used in thesimulations below are provided in Table 1 below. The composition ofmethane in the exemplary gases varies from 66% in the richest gas to 82%in the leanest gas sample. The molecular weight for the exemplarysamples varies from 20 to 24. The exemplary gas samples also show CO₂content of up to 6.9% and maximum H₂S content of up to 20 ppm whichmakes the gas generally corrosive.

TABLE 1 Non-limiting, exemplary gases Quickset Design Gas CompositionCase 4 Case 1 & 2 Sta # Sta # Sta # Sta # Sta # Table 2.1 SAMPLE MM0059MM0106 MM0132 MM0042 MM0046 Component Formula Nov. 17, 2016 Nov. 17,2016 Nov. 17, 2016 Nov. 17, 2016 Nov. 17, 2016 Hydrogen H2S 0.002 0 0 00 Sulfide Nitrogen N2N 2.838 2.513 3.666 2.573 2.873 Carbon CO2 2.5380.385 6.932 1.01 1.024 Dioxide Methane C1 66.925 68.709 70.106 69.5167.454 Ethane C2 13.322 14.662 8.071 12.434 13.794 Propane C3 8.5648.308 6.146 8.386 8.843 i-Butane iC4 0.901 0.755 0.728 0.974 0.939n-Butane nC4 2.791 2.407 2.315 2.956 2.875 i-Pentane iC5 0.619 0.5980.63 0.646 0.627 n-Pentane nC5 0.689 0.724 0.578 0.691 0.659 Hexane PlusC6+ 0.811 0.939 0.828 0.82 0.912 MW 24.277 23.6349 23.8733 23.77624.1184 Case 3 Sta # Sta # Sta # Table 2.1 SAMPLE MM0058 MM0073 Sta # MMMM0207 Sta # Component Formula Nov. 17, 2016 Nov. 17, 2016 Nov. 17, 2016Nov. 17, 2016 Mar. 3, 2017 Hydrogen H2S 0 0 0.001 0 0 Sulfide NitrogenN2N 4.036 5.8 4.451 3.286 2.395 Carbon CO2 0.915 4.32 7.511 2.143 0.619Dioxide Methane C1 67.971 82.457 69.042 73.642 70.688 Ethane C2 11.8534.971 8.278 10.004 12.516 Propane C3 8.098 1.12 6.102 6.163 8.5697i-Butane iC4 0.935 0.074 0.735 0.771 0.7442 n-Butane nC4 3.276 0.3252.059 2.164 2.5785 i-Pentane iC5 0.751 0.129 0.544 0.605 0.663 n-PentanenC5 0.9 0.169 0.478 0.531 0.6635 Hexane Plus C6+ 1.265 0.635 0.799 0.6910.5612 MW 24.3 19.785 23.95 22.59 23.198

An exemplary embodiment of an apparatus of the present disclosure isshown in FIG. 4. The intent of the quickset skid is to separate liquidsfrom the gas, meter and transfer the gas to the adjacent gas compressorskid, and discharge collected liquids from the charge vessel to a remotestorage facility. As shown in FIG. 4, production gas is fed to the inletseparator 2 on a gas lift skid 1 from a production gas feed 12. Theinlet separator 2 is configured to separate liquids from the productiongas to form a gas lift gas. The inlet separator is operatively connectedto a level controller 13 that is configured to open the inlet separatorlevel control valve 14 to dump the liquid from the inlet separator tothe charge vessel 3 via the inlet separator and compressor drain line 15when it is in excess of a target liquid level. The level controller 13is also configured to close the inlet separator level control valve 14when the liquid level in the inlet separator is below the target liquidlevel. The inlet separator is also configured with a safety valve 30 torelieve pressure if it exceeds a predetermined level. The charge vessel3 is similarly equipped with a safety valve 31 to relieve pressure if itexceeds a predetermined level. Gas lift gas produced by the inletseparator can flow along the gas line to the compressor 16 to berecompressed for use as gas lift gas in the well. The compressor system4 has a fuel gas inlet 17 via which it receives fuel gas from the gasline to the compressor 16. The compressor system 4 can also obtain gasfrom the charge vessel via the compressor suction line 18 which isequipped with a control valve 19 and can convey gas from the chargevessel 3 to the compressor system 4. Liquids from the compressor system4, such as from a fuel filter scrubber, an inlet scrubber and interstagescrubbers can be drained to the charge vessel 3 via the compressorsystem drain line 15 which is also the drain line for the inletseparator. However, liquids from environmental drains in the compressorsystem 4 are drained via a drain drum line 26 to a drain drum 27 andthen pumped by a drain pump 28 connected to an interstage, such as thefirst interstage, of the compressor system 4 via a fluid connection 29.The fluid connection 29 can also provide supply gas to the charge vessellevel controller 23 via a fluid connection 22 and to the control valve19, control valve 20 and the charge vessel drain valve 24 to operateeach valve based on the liquid level in the charge vessel 3. Gas from ahigh pressure gas source in the compressor system, such as the first orsecond interstage, can be fed along the a gas line 21 which is equippedwith a control valve 20 for pushing liquids out of the charge vesselwhen the charge vessel drain valve 24 is open and the compressor suctionline control valve is closed via the charge vessel drain line 25.

In operation, the apparatus separates liquids from the production gas inthe inlet separator 2, the liquids flowing into the charge vessel 3under level control from the inlet separator 2, while gas lift gas canflow to compressor system 4 for recompression. Liquids generated in thecompressor system, with the exception of environmental drains can thenflow to the charge vessel 3 with environmental drains being pumped fromthe drain drum 27 to the charge vessel 3 by the drain pump 28 which ispowered by gas from an interstage of the compressor system 4. When thelevel of liquid in the charge vessel 3 exceeds a predetermined limit,the charge vessel level controller 23 can close the compressor suctionline control valve 19 and open the charge vessel drain valve 24 and gasline control valve 20 to allow high pressure gas from the compressorsystem 4 to push the liquid out of the charge vessel 3. When the levelof liquid in the charge vessel is below a predetermined limit, the levelcontroller 23 can open the compressor suction line control valve 19 andclose the charge vessel drain valve 24 and gas line control valve 20.The dumped liquids can then be fed along the charge vessel drain line 25to the wellhead or tank battery.

In FIG. 4, the gas flow rate from the inlet separator 2 can be meteredby the origice meter on the outlet gas and transmitted by the flowtransmitter 77. By way of example, but not limitation, the metered gasflow rate can typically vary from 0.25 MMSCFD to 2.0 MMSCFD. Flowtransmitter signal from the flow transmitter 77 can be used to controlthe compressor suction valve on the adjacent skid. The flow transmittersignal can also be sent to a remote monitoring station via wirelesscommunication provisions.

The liquids from the inlet separator 2 can be under level control andcan discharged to the charge vessel 3 for subsequent transfer to aremote storage facility. Since liquids will typically condense in theinlet flow line from the production facility intermittent slugs mayarrive at the inlet separator 2. A level gauge can be provided on bothinlet and charge vessels.

Pressure in the inlet separator can, by way of example but notlimitation, vary between 15 PSIG and 250 PSIG depending on supply ratesfrom remote production facility and also the downstream compressordischarge capacity to the gas lift wells. At high operating pressure inthe inlet separator, gas can be relieved to atmosphere from the safetyvalve 30 which can be set, by way of example but not limitation, at 275PSIG.

The pressure in the charge vessel 3 would be set by the operatingpressure in the compressor suction scrubber as both vessels share acommon header and will normally equalize at the same operating pressure.While liquids are being displaced with utility gas the pressure in thecharge vessel 3 will increase, by way of example but not limitation, toapproximately 180 PSIG. During this operation, the compressor inletscrubber can be be isolated from the high pressure in the scrubber withclosure of level valve 19.

All liquid lines on the skid can be insulated and heat traced.

Table 2 below provides an exemplary set point register for controllerson the quickset set.

TABLE 2 Exemplary Set Point Register Tag No: Lower Range Upper Range SetPoint Unit LC-101 0 24 16 inches (13 in FIG. 4) LC-102 0 24 16 inches(23 in FIG. 4) PC-102A 0 250 180 PSIG (81 in FIG. 4) PC-102B 0 250 50PSIG (82 in FIG. 4)

Exemplary specifications of the embodiment shown in FIG. 4 are providedin Table 3 below.

TABLE 3 Exemplary specification for Apparatus of FIG. 4 DESIGNDESCRIPTION Inlet Separator Operating Pressure - 15 psi-250 Psi Flow -.250-2.0 MMSCFD Gas Composition - (see Table 1) Gas Metering Inlet Meteror Meters Built To American Gas Association and American PetroleumInstitute standards governed by AGA Report Number 3, Part 2 (API 14.3,Part 2). Tube Operating Pressure 15 psi-250 Psi Flow .250-2.0 MMSCFD GasAnalysis (see Table 1) Daniel Simplex Fitting Block & Bypass CapabilityEFM Total flow EFM/Battery/Solar Panel capable of wireless communication(RS 485) of flow/pressure data with control functionality so that tocontrol an actuated suction control valve based off a pressure setpoint. Charge Vessel Vessel capable of receiving and automatically blowcasing fluids to customers poly flow line from tubing of well to offsitetank battery (CTB) from the following, Compressor Skid Drains (Pumpedvia diaphragm pump) 60 psi max Inlet Separator 15 psi-250 Psi Gas fromInlet Separator Compressor Operation will discharge to Adjacent InletScrubber 15-125 Psi Compressor Skid. 1st Interstage Scrubber 100-450 psiLiquids will return from 2nd Interstage Scrubber 200-600 psi interstagescrubber Fuel Gas Filter Scrubber 50-150 psi to Charge Vessel.

The production gases to processed on the quickset skid can have H₂Scontent which can typically range from 0 to 20 ppm. The currentprovisions are for venting local discharge to atmosphere. This caninclude discharge from the safety valve on the inlet separator andcharge vessel and periodic blowdown from the compressor on the adjacentcompressor skid.

Since H₂S and CO₂ gases are both heavier than air, they may concentrateat lower elevation, particularly with conditions of low wind velocityand low temperature in winter months. This could present a safety hazardto personnel at the site. The vent piping from the safety valve andcompressor blowdown can be located at sufficient heights to provide gooddispersion of the vent gases away from the facility.

A summary of exemplary environmental data for the apparatus in FIG. 4are provided in Table 4 below.

TABLE 4 Exemplary environmental data for FIG. 4 ITEM DESCRIPTION VALUEUNITS Barometric Pressure Pressure 14.7 PSIA Ambient TemperatureMaximum - Design 120 ° F. Operation 20-90 ° F. Minimum Design −20 ° F.Air Cooler - Design 100 ° F. Max. Wind Design Code ASCE 7-95 DesignVelocity 96 MPH Exposure Factor Category Importance Factor 1.15Prevailing Direction TBD Relative Humidity Design 75.00% Ice/Frost Line,Below Design Inches Surface Hydrate Line ° F. Site Elevation Design FeetAbove MSL Design TBD Feet Above MSL Rainfall Annual Average 20 InchesMonthly-Max. 25 Inches 24 Hour-25 Yr Max. 1 Inches 1 Hour-25 Yr Max 1Inches 1 Hour-10 Yr. MAX 1.25 Inches Snowfall Annual Average 3 InchesSeismic

A summary of exemplary design conditions is provided in Table 5 below.

TABLE 5 Exemplary Design Conditions Inlet Separator Size 2′-0″ OD ×10′-0″ T/T Design 275 PSIG @ 120/−20° F. Operation 20/250 PSIG @ 60° F.Residence time 4 minutes Charge vessel Size 2′-0″ OD × 8′-0″ T/T Design275 PSIG @ 120/−20° F. Operation 15/200 PSIG @ 260° F. Residence time 5minutes

An exemplary instrument list for FIG. 4 is provided in Table 6 below.

TABLE 6 Instrument List for FIG. 4 Instrument Tag Description RangeUnits FIT-101 (78) Gas flow rate from 0-3.0 MMSCFD inlet separatorV-101. LG-101 (79) Liquid Level in 0-24 Inches Separator V-101 LG-102(80) Liquid Level in 0-24 Inches Separator V-102 LC-101 (13) Levelcontroller for separator V-101 LCV-101 (14) Level control valve fromseparator V-101 LC-102 (23) Level controller for separator V-102LCV-102A (24) Level control valve from separator V-102 LCV-102B (19)Level control valve from separator V-102 LCV-102C (20) Level controlvalve to separator V-102 TW/TI-101 (85) Temperature in V- 0-150 ° F. 101TW-101A (84) Temperature 0-150 ° F. downstream V-101 PI-101A (83)Pressure in Inlet 0-350 PSIG separator V-101 PI-102 (86) Pressure inCharge 0-350 PSIG Vessel V-102 PCV-102A (81) Pressurizing Charge vesselgas supply V- 102 PCV-102B (82) Instrument gas to LC- 102 PSV-101 (30)Safety valve on Inlet set@275 PSIG Separator V-101 PSV-102 (31) Safetyvalve on set@275 PSIG Charge Vessel V-102

The pipe material recommended is carbon steel with 0.125″ corrosionallowance. Since Carbon steel will corrode in the atmosphere, a suitablecoating system should be applied. No additional corrosion allowance forexternal corrosion, above the specified corrosion allowance for internalcorrosion is required.

The inlet separator and charge vessel can be insulated and heat tracedto minimize potential for icing. All liquid lines on the quickset skidcan be insulated and heat traced.

FIG. 5 shows an apparatus quickset skid setup used for simulations. Theapparatus includes the inlet separator 2 which is connected to thecharge vessel 3 and configured to deliver liquids to the charge vesselvia the drain line 15 which also can drain liquids from the inletscrubber 6, first interstage scrubber 7 and second interstage scrubber 8in the compressor system which includes the compressor 10. The liquidsfrom the inlet scrubber are pumped via the pump 7 to the charge vessel3. The production gas is fed to the inlet scrubber via the feed 12 andgas is conveyed by the gas line to the compressor system 16. Thecompressor suction line 18 can direct gas from the charge vessel 3 tothe compressor system and into the inlet scrubber 6. Recompressed gasfrom the compressor system can flow to well via piping 32.

Simulations were performed according to the parameters in Table 7 usingthe apparatus of FIG. 5. The cases considered would cover the worstdesign condition anticipated during normal operation. The inlet feedwill normally condense some liquids and up to 5 BWPD nominally isassumed in the feed to the quickset skid. Liquids removal rate from thequickset skid inlet separated and charging vessel are also shown inTable 7. Generally, the colder the inlet operating conditions, the moreliquids will be removed from the quickset skid and will be transferredto the remote tank farm storage facility. Up to 94 BPD of liquids willdischarge to the tank farm with a low winter operating inlet temperatureof 20° F.

TABLE 7 Inlet and Outlet Properties for Simulations Inlet Charging GasInlet Sep. Water Rate Sep. Oil Water outlet CASES DESCRIPTION (MMSCFD)(BOPD) (BWPD) (BLPD) 1 Maximum arrival pressure of 2 20 5 25.6 250 PSIG@ 60 F. - Rich gas feed composition using sample #46 2 Low arrivalpressure of 20 2 0 5 5.7 PSIG @ 60 F. - Rich gas feed using sample #46 3Maximum arrival pressure of 2 0 5 5 250 PSIG @ 60 F. - Lean gas feedcomposition using sample #73 4 Maximum arrival pressure of 2 16 5 21 250PSIG @ 60 F. - Rich gas feed composition using sample #59 5 Maximumarrival pressure of 2 89 5 94.5 250 PSIG @ 20 F. - Rich gas feedcomposition using sample #59

For each simulation, the properties for each flow are shown in Table 8below.

TABLE 8 Temperature, Pressure and Flow Properties for Simulation Casesin Table 7 Temp- erature Pressure Case Flow Line (° F.) (psig) Flow 1 12(feed) 60.0 200.00 5264.01 lb/h 15 (liquid drain from 59.4 195.00 25.298separator) bbl/d 16 (gas from separator to 59.4 195.00 1.9772 compressorsystem) MMSCFD 18 (compressor suction line) 59.1 190.00 0.1 lb/h 25(charge vessel drain line) 59.2 187.00 25.676 bbl/d 32 (line to well)120.0 1005.00 1.9772 MMSCFD 2 12 (feed) 60.0 20.00 5264.01 lb/h 15(liquid drain from 59.7 19.00 4.965 separator) bbl/d 16 (gas fromseparator to 59.7 19.00 2.0148 compressor system) lb/h 18 (compressorsuction line) 47.5 15.00 0.00 lb/h 25 (charge vessel drain line) 67.510.00 5.700 bbl/d 32 (line to well) 120.00 2005.0 2.0094 MMSCFD 3 12(feed) 60.0 200.00 4334.14 lb/h 15 (liquid drain from 59.6 195.00 5.003separator) bbl/d 16 (gas from separator to 59.6 195.00 2.0025 compressorsystem) MMSCFD 18 (compressor suction line) 59.6 178.00 0.00 lb/h 25(charge vessel drain line) 59.7 175.00 5.001 bbl/d 32 (line to well)120.0 1005.0 2.0025 MMSCFD 4 12 (feed) 60.0 200.00 5318.56 lb/h 15(liquid drain from 59.4 195.00 20.933 separator) bbl/d 16 (gas fromseparator to 59.4 195.00 1.9826 compressor system) MMSCFD 18 (compressorsuction line) 59.1 190.00 0.08 lb/h 25 (charge vessel drain line) 59.2187.00 21.243 bbl/d 32 (line to well) 120.0 1005.00 1.9826 MMSCFD 5 12(feed) 20.0 200.00 15 (liquid drain from 19.3 195.00 94.689 separator)bbl/d 16 (gas from separator to 19.3 195.00 2.1794 compressor system)MMSCFD 18 (compressor suction line) 19.0 190.00 0.46 lb/h 25 (chargevessel drain line) 19.0 187.00 94.589 bbl/d 32 (line to well) 120.01005.00 2.1796 MMSCFD

The compressor power for each case is shown in Table 9 below.

TABLE 8 Compressor Power Requirements for Simulation Cases in Table 71^(st) Stage 2^(nd) Stage 3^(rd) Stage Total Power Case Power PowerPower (hp) 1 69.51 60.63 57.29 187.43 2 158.69 164.87 119.85 443.41 389.35 84.63 63.01 236.99 4 69.68 60.78 57.40 187.87 5 91.20 52.36 53.87197.44

As shown in FIGS. 6A and 6B, which depict another embodiment of the gaslift skid 1, the apparatus includes an inlet separator 2 and a chargevessel 3 on a skid 11. The inlet separator 2 receives gas from anoff-site central tank battery or pipeline at the inlet 52. The chargevessel 3 has a charge gas liquid outlet 25 to well stream flow line tocentral tank batter. HP de pressure line 33 is between the inletseparator 2 and charge vessel 3. LP de pressure line 24 is connected topressure line 33 to connect to engine fuel gas, compressor suction oratmosphere. Compressor suction meters 35 are also mounted on the skid11. The charge vessel 3 has an HP charge gas inlet 36 from firstinterstage, second interstage, third interstage, or final discharge fromthe compressor. The charge vessel 3 further has an HP liquid inlet 37and a LP liquid inlet 38 pumped via diaphragm or electric pump.

Another exemplary apparatus of the present disclosure is depicted inFIG. 7. As shown in FIG. 7, the apparatus according to anotherembodiment of a gas lift skid 1 includes an inlet separator 2, a LPcharge vessel 50, and a HP charge vessel 51 on a skid. Inlet separator 2receives gas from offsite central tank battery or pipeline at inlet 52from the feed 12. Liquids are separated from inlet gas stream and areautomatically dumped via inlet separator automatic level controller 13from inlet separator dump valve 45 through the liquid outlet 54 into LPcharge vessel 50 through a liquid inlet 59 on the LP charge vessel 50.Dry gas from inlet separator 2 passes through a gas lift gas outlet 53then travels through meter or meters 57 to compressor suction via onskid interconnected piping connection 74. Further Meters 57 are equippedwith bypass piping. LP charge vessel 50 receives low pressure liquidsfrom on skid interconnected piping connection 58 from the fuel gasscrubber, suction scrubber, first inter stage scrubber, and skid drainsof associated gas lift compressor, or any liquids stream with anoperating pressure greater than 20 psig. Liquids from LP Charge Vessel50 are automatically dumped through a liquid outlet 87 via LP chargevessel level control 63 through the LP charge vessel dump valve 40 viainterconnected piping to the gas lift skid liquid outlet line 65 to wellstream flow line to offsite central tank battery or on-site productiontank. LP charge vessel 50 receive high pressure charge gas through LPcharge gas valve 46 automatically via output signal from LP chargevessel liquid level controller 63 from first inter stage, second interstage, or final discharge of associated compressor or alternative highpressure gas source that is greater than well flow line pressure viainterconnected on skid piping connection 66 that has an automaticpressure regulator 49. LP charge vessel 50 de pressures to inletseparator 2 through the a gas de pressure outlet 60 via LP charge vesselde pressure valve 42 automatically via output signal from LP chargesvessel automatic level controller 63. LP charge vessel 50 further depressures through a gas outlet 62 via a LP charge vessel fuel line thatflows into a gas inlet 69 on a the fuel filter and is filtered via onskid fuel filter 68 that connects to associated compressor engine fuelline via on skid interconnected piping connection 67 and allows gas toflow from the gas outlet 71 on the fuel filter. LP charge vessel 50 fuelline has an automatic fuel gas pressure regulator 48. LP charge vesselfuel line further has an automatic pressure makeup valve 43 from whichit supplies fuel gas from inlet separator 2 through a gas make up outlet55 automatically. LP fuel gas filter 68 has an automatic levelcontroller 72 which automatically introduces higher pressure gas frominlet separator 2 through a gas charge outlet to the fuel filter 56 viaoutput signal to fuel gas filter charge valve 44 allowing fluids to dumpinto LP charge vessel 50 through the fuel filter liquid outlet 70 via onskid interconnecting piping. The HP charge vessel 51 receives liquidsfrom the associated first and/or second inter stage compressor scrubbersor alternative liquid source that has an operating pressure greater thanthe well flow line pressure via on skid interconnecting pipingconnection 73 through the liquid inlet 75 of the HP charge vessel.Liquids from HP charge vessel 51 are automatically dumped via HP chargevessel level control 64 through the HP charge vessel dump valve 41 outof the liquid outlet 76 of the HP charge vessel via interconnectedpiping to the gas lift skid liquid outlet line 65 to well stream flowline to offsite central tank battery or an onsite production tank. HPcharge vessel 51 receives high pressure charge gas through HP charge gasvalve 47 automatically via output signal from HP charge vessel liquidlevel controller 64 from first inter stage, second inter stage, or finaldischarge of associated compressor via interconnected on skid pipingconnection 66 that has an automatic pressure regulator 49. The HP chargevessel separator 51 further has an automatic controlled pressureregulating valve 39 connected to relieve excess gas pressure to theinlet separator 2.

It should be understood that the foregoing description providesembodiments of the present invention which can be varied and combinedwithout departing from the spirit of this disclosure. To the extent thatthe different aspects disclosed can be combined, such combination aredisclosed herein.

Those of skill in the art should, in light of the present disclosure,appreciate that many changes can be made in the specific embodimentswhich are disclosed and still obtain a like or similar result withoutdeparting from the concept, spirit and scope of the present disclosure.

What is claimed is:
 1. An apparatus comprising: an inlet separatorconfigured to receive production gas and to separate entrained liquidsfrom the production gas to form a gas lift gas, the inlet separatorcomprising: a production gas inlet, a gas lift gas outlet configured tobe fluidically connected to a compressor system comprising at least oneengine capable of being operated using the gas lift gas as fuel, and aliquid outlet, a first charge vessel, comprising: a first liquid inletfluidically connected to the liquid outlet of the inlet separator, afirst charge gas valve configured to be fluidically connected to a highpressure gas source in said compressor system and further configured todeliver high pressure gas to drain the first charge vessel when thefirst charge gas valve is in an open configuration, a liquid outletfluidically connected to a first dump valve, the first dump valveallowing liquid from the first charge vessel to flow out of the firstcharge vessel when the first dump valve is in an open position andpreventing the flow of liquid from the first charge vessel when thefirst dump valve is in a closed position, and a gas outlet configured tobe fluidically connected to the at least one engine.
 2. The apparatus ofclaim 1, wherein the first liquid inlet of the first charge vessel isconfigured to be fluidically connected to the compressor system toreceive liquids from the compressor system.
 3. The apparatus of claim 1,the first charge vessel comprising a second liquid inlet configured tobe fluidically connected to the compressor system to receive liquidsfrom the compressor system.
 4. The apparatus of claim 2, wherein thefirst liquid inlet is configured to receive liquids from at least onesource chosen from an inlet or suction scrubber, a fuel filter, aninterstage scrubber and environmental drains of the compressor system.5. The apparatus of claim 3, wherein the second liquid inlet isconfigured to receive liquids from at least one source chosen from aninlet or suction scrubber, a fuel filter, an interstage scrubber andenvironmental drains of the compressor system.
 6. The apparatus of claim1, wherein the high pressure gas source is a gas source with a pressuregreater than the pressure in the first charge vessel.
 7. The apparatusof claim 1, wherein the high pressure gas source is chosen from a firstinterstage scrubber, a second interstage scrubber, a third interstagescrubber and a final discharge of gas from the compressor system.
 8. Theapparatus of claim 1, wherein the high pressure gas source is a secondinterstage scrubber of the compressor system.
 9. The apparatus of claim1, further comprising a fuel filter comprising: a gas inlet, a liquidoutlet, and a gas outlet configured to be fluidically connected to theat least one engine capable of being operated using the gas lift gas asfuel in the compressor system, the fluidic connection between the gasoutlet and the at least one engine comprising a pressure control valveconfigured to allow a suitable pressure of gas lift gas to the at leastone engine to operate the at least one engine, wherein the gas inlet ofthe fuel filter is fluidically connected to gas outlet of the firstcharge vessel.
 10. The apparatus of claim 9, further comprising apressure sensor configured to detect a pressure to the at least oneengine, configured to be positioned between the pressure control valveand the compressor system, the inlet separator further comprising a gasmake up outlet fluidically connected to the fuel filter, the fluidconnection between the gas make up outlet and the fuel filter comprisinga fuel gas make up valve, the fuel gas make up valve being configured toallow sufficient gas lift gas to flow from the inlet separator to thefuel filter to maintain a pressure suitable to operate the at least oneengine, the pressure sensor being operatively connected to the gas makeup valve and configured to open or close the gas make up valvesufficiently to deliver a suitable pressure of gas lift gas to the atleast one engine to operate the at least one engine.
 11. The apparatusof claim 9, the inlet separator further comprising a gas charge outletfluidically connected to the fuel filter, the fluidic connection betweenthe gas charge outlet and the fuel filter comprising a fuel filtercharge valve configured to deliver a gas lift gas to the fuel filter todrain liquids from the fuel filter when the fuel filter charge valve isin an open configuration.
 12. The apparatus of claim 10, the inletseparator further comprising a gas charge outlet fluidically connectedto the fuel filter, the fluidic connection between the gas charge outletand the fuel filter comprising a fuel filter charge valve configured todeliver a gas lift gas to the fuel filter to drain liquids from the fuelfilter when the fuel filter charge valve is in an open configuration.13. The apparatus of claim 1, further comprising a charge gas pressureregulator fluidically connected to the first charge gas valve, thecharge gas pressure regulator being configured to be fluidicallyconnected to the high pressure gas source between the high pressure gassource and the first charge gas valve, the charge gas pressure regulatorbeing configured to deliver a target charge gas pressure.
 14. Theapparatus of claim 1, the first charge vessel comprising a gas depressure outlet fluidically connected to the inlet separator, thefluidic connection between the gas de pressure outlet and the inletseparator comprising a de pressure valve.
 15. The apparatus of claim 14,further comprising a first level controller operatively connected to thefirst charge vessel, the de pressure valve, the first charge gas valveand the first dump valve, the first level controller being configured toclose the de pressure valve between the first charge vessel and theinlet separator, open the first charge gas valve and open the first dumpvalve when a liquid level in the first charge vessel exceeds a firsttarget liquid level, and the first level controller being configured toopen the de pressure valve between the first charge vessel and the inletseparator, close the first charge gas valve, and close the first dumpvalve when the liquid level in the first charge vessel is less the firsttarget liquid level.
 16. The apparatus of claim 15, wherein the inletseparator is fluidically connected to the first level controller. 17.The apparatus of claim 1, further comprising a second level controlleroperatively connected to the inlet separator, the fluidic connectionbetween the liquid outlet of the inlet separator and the liquid inlet ofthe first charge vessel comprising an inlet separator dump valveoperatively connected to the second level controller, the second levelcontroller being configured to open the inlet separator dump valve whena liquid level in the inlet separator exceeds a second target liquidlevel, and the second level controller being configured to close theinlet separator dump valve when the liquid level in the inlet separatoris less than the second target liquid level.
 18. The apparatus of claim17, wherein the inlet separator is fluidically connected to the secondlevel controller.
 19. The apparatus of claim 15, further comprising asecond level controller operatively connected to the inlet separator,the fluidic connection between the liquid outlet of the inlet separatorand the liquid inlet of the first charge vessel comprising an inletseparator dump valve operatively connected to the second levelcontroller, the second level controller being configured to open theinlet separator dump valve when a liquid level in the inlet separatorexceeds a second target liquid level, and the second level controllerbeing configured to close the inlet separator dump valve when the liquidlevel in the inlet separator is less than the second target liquidlevel.
 20. The apparatus of claim 19, wherein the inlet separator isfluidically connected to the second level controller.
 21. The apparatusof claim 11, further comprising a third level controller operativelyconnected to the fuel filter, the third level controller beingconfigured to open the fuel filter charge valve when a liquid level inthe fuel filter exceeds a third target liquid level, and the third levelcontroller being configured to close the fuel filter charge valve whenthe liquid level in the fuel filter is less than the third target liquidlevel.
 22. The apparatus of claim 21, wherein the inlet separator isfluidically connected to the third level controller.
 23. The apparatusof claim 1, further comprising at least one flow meter fluidicallyconnected to the gas lift gas outlet, the at least one flow meterconfigured to measure the flow rate of gas or to limit the flow of gasto the compressor system.
 24. The apparatus of claim 1, furthercomprising a second charge vessel, the second charge vessel comprising:at least one liquid inlet configured to be fluidically connected to thecompressor system to receive liquids from the compressor system, asecond charge gas valve configured to be fluidically connected to thehigh pressure gas source in said compressor system and furtherconfigured to deliver high pressure gas to drain the second chargevessel when the second charge gas valve is in an open configuration, aliquid outlet fluidically connected to a second dump valve, the seconddump valve allowing liquid from the second charge vessel to flow out ofthe second charge vessel when the second dump valve is in an openposition and preventing the flow of liquid from the second charge vesselwhen the second dump valve is in a closed position.
 25. The apparatus ofclaim 24, the second charge vessel being configured to receive liquidsfrom a second interstage of the compressor system.
 26. The apparatus ofclaim 24, further comprising a fourth level controller operativelyconnected to the second charge vessel, the second charge gas valve andthe second dump valve, the fourth level controller being configured toopen the second charge gas valve and open the second dump valve when aliquid level in the second charge vessel exceeds a fourth target liquidlevel, and the fourth level controller being configured to close thesecond charge gas valve, and close the second dump valve when the liquidlevel in the second charge vessel is less than the fourth target liquidlevel.
 27. The apparatus of claim 26, wherein the inlet separator isfluidically connected to the fourth level controller.
 28. The apparatusof claim 24, further comprising a charge vessel pressure regulatorfluidically connected to the second charge vessel and to the inletseparator, the charge vessel pressure regulator being configured torelieve excess pressure in the second charge vessel.
 29. A method forrecovering a gas lift gas and liquids from production gas, comprising:feeding a production gas to the apparatus of claim 1 through theproduction gas inlet of the inlet separator; allowing gas lift gas fromthe first charge vessel to flow into the at least one engine in thecompressor system, the gas outlet of the first charge vessel beingfluidically connected to the at least one engine, the gas lift gas beingsuitable to operate the at least one engine.
 30. The method of claim 29,further comprising: allowing a first portion of liquids generated by thecompressor system to flow into the first charge vessel, wherein thefirst charge vessel is fluidically connected to a source of the firstportion of liquids generated by the compressor system; and pushing theliquid in the first charge vessel out of the first charge vessel usingthe high pressure gas source from the compressor system, the firstcharge vessel being fluidically connected to the high pressure gassource.